<?php

namespace Tests\Unit;

use App\Models\User;
use Illuminate\Foundation\Testing\RefreshDatabase;
use Tests\TestCase;

class UserHashEmailTest extends TestCase
{
    use RefreshDatabase;

    public function test_hash_uses_hmac_sha256_with_app_key(): void
    {
        $email = 'test@example.com';
        $hash = User::hashEmail($email);

        $expectedHash = hash_hmac('sha256', strtolower(trim($email)), config('app.key'));
        $this->assertEquals($expectedHash, $hash);

        $plainSha256Hash = hash('sha256', strtolower(trim($email)));
        $this->assertNotEquals($plainSha256Hash, $hash, 'HMAC-SHA256 should be different from plain SHA-256');
    }

    public function test_hash_is_deterministic(): void
    {
        $email = 'test@example.com';

        $hash1 = User::hashEmail($email);
        $hash2 = User::hashEmail($email);

        $this->assertEquals($hash1, $hash2, 'Same email should produce the same hash');
    }

    public function test_hash_is_case_insensitive(): void
    {
        $email1 = 'test@example.com';
        $email2 = 'TEST@EXAMPLE.COM';
        $email3 = 'TeSt@ExAmPlE.cOm';

        $hash1 = User::hashEmail($email1);
        $hash2 = User::hashEmail($email2);
        $hash3 = User::hashEmail($email3);

        $this->assertEquals($hash1, $hash2, 'Uppercase email should produce the same hash');
        $this->assertEquals($hash1, $hash3, 'Mixed case email should produce the same hash');
    }

    public function test_hash_trims_whitespace(): void
    {
        $email1 = 'test@example.com';
        $email2 = '  test@example.com  ';
        $email3 = "\ttest@example.com\n";

        $hash1 = User::hashEmail($email1);
        $hash2 = User::hashEmail($email2);
        $hash3 = User::hashEmail($email3);

        $this->assertEquals($hash1, $hash2, 'Email with leading/trailing spaces should produce the same hash');
        $this->assertEquals($hash1, $hash3, 'Email with tabs/newlines should produce the same hash');
    }

    public function test_different_emails_produce_different_hashes(): void
    {
        $email1 = 'user1@example.com';
        $email2 = 'user2@example.com';
        $email3 = 'admin@example.com';

        $hash1 = User::hashEmail($email1);
        $hash2 = User::hashEmail($email2);
        $hash3 = User::hashEmail($email3);

        $this->assertNotEquals($hash1, $hash2, 'Different emails should produce different hashes');
        $this->assertNotEquals($hash1, $hash3, 'Different emails should produce different hashes');
        $this->assertNotEquals($hash2, $hash3, 'Different emails should produce different hashes');
    }

    public function test_find_by_email_method_works_correctly(): void
    {
        $email = 'findme@example.com';
        $emailHash = User::hashEmail($email);

        $this->assertNull(User::findByEmail($email), 'User should not exist yet');

        $user = User::create([
            'email_hash' => $emailHash,
        ]);

        $foundUser = User::findByEmail($email);

        $this->assertNotNull($foundUser, 'User should be found');
        $this->assertEquals($user->id, $foundUser->id, 'Found user should match created user');
        $this->assertEquals($emailHash, $foundUser->email_hash, 'Email hash should match');
    }

    public function test_find_by_email_is_case_insensitive(): void
    {
        $email = 'case@example.com';
        $emailHash = User::hashEmail($email);

        $user = User::create([
            'email_hash' => $emailHash,
        ]);

        $foundUser1 = User::findByEmail('case@example.com');
        $foundUser2 = User::findByEmail('CASE@EXAMPLE.COM');
        $foundUser3 = User::findByEmail('CaSe@ExAmPlE.cOm');

        $this->assertNotNull($foundUser1);
        $this->assertNotNull($foundUser2);
        $this->assertNotNull($foundUser3);

        $this->assertEquals($user->id, $foundUser1->id);
        $this->assertEquals($user->id, $foundUser2->id);
        $this->assertEquals($user->id, $foundUser3->id);
    }

    public function test_find_by_email_trims_whitespace(): void
    {
        $email = 'trim@example.com';
        $emailHash = User::hashEmail($email);

        $user = User::create([
            'email_hash' => $emailHash,
        ]);

        $foundUser = User::findByEmail('  trim@example.com  ');

        $this->assertNotNull($foundUser);
        $this->assertEquals($user->id, $foundUser->id);
    }

    public function test_hash_length_is_consistent(): void
    {
        $emails = [
            'a@b.c',
            'test@example.com',
            'very.long.email.address@subdomain.example.com',
        ];

        $hashes = array_map(fn($email) => User::hashEmail($email), $emails);

        foreach ($hashes as $hash) {
            $this->assertEquals(64, strlen($hash), 'SHA-256 hash should always be 64 characters');
        }
    }

    public function test_hash_contains_only_hexadecimal_characters(): void
    {
        $email = 'test@example.com';
        $hash = User::hashEmail($email);

        $this->assertMatchesRegularExpression(
            '/^[a-f0-9]{64}$/',
            $hash,
            'Hash should contain only lowercase hexadecimal characters'
        );
    }
}